Practice-Based Research Network Cancer Control Training (PBRN-CCT) Practice-Based Research Networks (PBRNs) have emerged as powerful laboratories for research at the front lines of medical care where most cancer preventive services are delivered. However, PBRNs have rarely been systematically engaged as community laboratories for cancer control research. Building on a decade of experience with NCI-funded research as a partnership between a PBRN and an NCI-designated comprehensive cancer center, we propose to train a new generation of cancer control researchers who will be experienced in conducting research with PBRNs. This will be accomplished through a 2-3 year post-doctoral fellowship to train clinician-researchers (physicians, dentists, doctorally-prepared nurses) to conduct cancer control research in PBRNs. A multidisciplinary mentorship team will guide each fellow's training and development with both community and academic membership. Fellows will engage in an intensive core curriculum. In addition, a highly individualized longitudinal curriculum will include flexible opportunities for education to meet their specific needs, including an option for a master's degree in public health. Fellows will develop and conduct their own cancer control research project in partnership with a PBRN, and will gain experience in facilitating clinician-initiated research. Fellows will maintain their clinical skills and gain additional insights by practicing in a PBRN practice. This integrated post-doctoral program will prepare fellows for careers as academic cancer control researchers who possess the skills and relationships to generate important new knowledge, and the ability to successfully translate research findings into real world practice.